The invention relates generally to the copying of a master.
More particularly, the invention relates to the copying of a transparency on photosensitive material where the latter is exposed to light of the primary colors blue, green and red.
For photographs having individual areas with large brightness differentials, the copies are often overexposed in the light regions and underexposed in the dark regions. As a result, details and fine structures are poorly visible or completely invisible on the copies.
The German patent 28 20 965 discloses a copying apparatus having a liquid crystal display between the light source and the film. A black-and-white negative mask of an exposure to be reproduced is formed on this display by means of an electric control mechanism. When the copy paper is now exposed using light which has passed through the mask and the exposure, a desired density compression is achieved. However, it has been found that color errors are present in the copies.